About 1 million adult Californians seek health care in Mexico each year – and that figure is probably growing as the recession expands the ranks of the uninsured who are drawn to cheaper care south of the border, said the lead researcher of the first major report on the topic, released yesterday.

These people live from the Bay Area to San Diego County. Most go to Mexico for prescription drugs and dental care, and a smaller number go for surgeries. Beyond finances, other factors prompting individuals to head south include language and cultural barriers.

Living within 15 miles of the border also greatly increases the likelihood of someone obtaining health services in Mexico.

Angela Tapia, 45, of San Ysidro crosses the border several times each year to see her gynecologist. She also had back surgery in Tijuana a decade ago.

“It's cheaper to go there,” said Tapia, who doesn't have health insurance. “When you go to those doctors, they give you time, they ask a lot of questions and they care about you.”

Roughly half of the cross-border patients are Mexican immigrants, a statistic that should challenge the popular notion of Mexican workers burdening California's hospitals and clinics by receiving all of their health care on this side of the border, said UCLA public health professor Steven Wallace, lead author of the new report.

“(Some) immigrants are facing barriers to receiving care in the United States, and they are turning to Mexico for that care,” said Wallace, who also serves as associate director of UCLA's Center for Health Policy Research.

Hospitals in this state spend about $700 million annually on emergency-room services for illegal immigrants, according to a 2007 estimate by the California Hospital Association in Sacramento. The figure is roughly 10 percent of all money that hospitals spend on free care.

About half a million U.S. citizens living in California also seek health services in Mexico, Wallace and his UCLA colleagues found.

Altogether, about 4 percent of adult Californians traveled to Mexico for some type of medical care.

Wallace's study was published yesterday in Medical Care, a journal for the American Public Health Association.

He and his fellow researchers based their analysis on data from the 2001 California Health Interview Survey, which questioned more than 55,000 random households across the state.

The wide-ranging survey, conducted every two years, is funded by agencies and groups including the state Department of Public Health, the National Cancer Institute and the California Endowment. Those done since 2001 haven't asked about accessing health care south of the border.

Wallace's group was the first to delve deeply into the statistics on medical treatment in Mexico. Previous research relied on anecdotal accounts or small, localized populations.

The cross-border trend probably will intensify as the number of Mexican immigrants living in California increases and the recession costs more people their jobs and health insurance coverage, Wallace said.

Between 2001 and 2007, the population of Mexican immigrants in California grew by 756,000 to 4.6 million, according to the Center for Immigration Studies in Washington, D.C.